Regional calendars

The short answer

This site's main calendar is the Vikram Samvat Panchang, in the Chaitradi and Purnimanta style, with the Amanta month name shown beside it. It is widely used in North India. The pages in this section describe the other calendars that Indian families use, in the home regions and in the diaspora.

These calendars are not rivals. They are different ways of measuring the same sky. Most of them agree on the major lunar festivals, such as Diwali and Maha Shivaratri. They differ in how they name months, when they start the year, and what year number they print.

Why India has several calendars

A year is about 365 days, and a lunar month about 29.5 days. Twelve lunar months fall short of a solar year by about eleven days. Any calendar must choose what to follow, and different regions made different choices over many centuries.

• Solar calendars follow the Sun. Each month begins when the Sun enters a zodiac sign. This keeps the months in the same season every year. Tamil, Malayalam, Bengali, Odia, Nepali and Nanakshahi calendars are of this kind.
• Lunisolar calendars follow the Moon for the months and add an extra month from time to time to keep in step with the Sun. Vikram Samvat, the Shaka-based Telugu, Kannada and Marathi calendars, the Gujarati calendar and the Jain calendar are of this kind.

Then there are two choices within lunar months. In the Purnimanta system, a month ends on the full moon. In the Amanta system, it ends on the new moon. This changes the name given to the dark fortnight, though not the day on which the festival falls.

Another reason is history. Each region kept an almanac tradition, often under local rulers and scholars, with its own era. Each year count begins from an event that mattered to that community: a king's reign, a teacher's birth, a founding. These eras were never merged.

After independence, India's Calendar Reform Committee studied the question in the 1950s, and the government adopted the Indian national calendar, a solar calendar based on the Shaka era, in 1957. It is used for official purposes alongside the Gregorian calendar, but families continued with their traditional almanacs for religious life.

Comparison

The "or" in each year rule depends on whether the New Year has arrived yet. Each regional page explains its own rule. Sources differ in some details, for example the Odia era and the origin of the Bangabda, and those pages say so.

What stays the same everywhere

The day itself is counted from sunrise to sunrise in nearly all of these traditions. The five limbs of the Panchang (tithi, vara, nakshatra, yoga and karana) are the same. A festival such as Diwali or Maha Shivaratri falls on the same tithi in every region that keeps it, though the month name may differ.

What changes is the label. For example, a festival that the main pages place in Phalguna Krishna is in Magha Krishna in an Amanta almanac. It is the same night.

Regional festivals

Several festivals belong to solar calendars and fall on nearly the same date every year. Mid April brings many of them together, because the Sun enters Mesha: Puthandu in Tamil Nadu, Vishu in Kerala, Poila Boishakh in Bengal, Bihu in Assam, Maha Vishuva Sankranti in Odisha, Baisakhi in Punjab and the New Year in Nepal. Pongal and Makar Sankranti belong to the winter day when the Sun turns north. Onam follows the Malayalam month of Chingam and the Thiruvonam star. Ugadi opens the year for Telugu and Kannada speakers.

Which should you use

Use the calendar your family or temple uses. If you are unsure, begin with the main Panchang on this site and check the regional pages for your community's New Year, month names and special days. If your temple or elders give a different day, follow them. Where traditions differ, this is a normal part of a living calendar.